OER UNIT 4 PARTITION

Data warehouse Design Using Oracle
https://www.oercommons.org/authorin
g/edit/21861
Dr. Girija Narasimhan 1
OER- UNIT 4 PARTITION

PARTITION
TABLESPACE
2Dr.Girija Narasimhan

Oracle Database allocates logical
space for all data in the
database.
The logical units of database
space allocation are data blocks,
extents, segments, and
tablespaces.
At a physical level, the data is
stored in data files on disk
The data in the data files is
stored in operating system
blocks.

Data blocks are the smallest
units storing data in the
oracle database
An extent is a set of logically
contiguous data blocks
allocated for storing a specific
type of information
A segment is a set of extents
allocated for a specific
database object, such as a
table.
Each segment belongs to one
and only one tablespace

The database has one or more table space.
Table space is called as logical storage unit within an oracle
database.
The meaning of logical is table space is not visible in the file
system.
Table space has at least had one data file. Each table space has
unique data file.
Each table space is divided into based on the size mentioned in
the “Create tablespace” statement.
The table space builds the bridge between the oracle database
and the file system in which the table’s or index data is stored

CREATE TABLESPACE dwuser01a
DATAFILE 'c:tempdwuser1a.dbf' SIZE 40M
BLOCKSIZE 8192
EXTENT MANAGEMENT LOCAL UNIFORM SIZE 256K
SEGMENT SPACE MANAGEMENT AUTO ONLINE;
In the Lab session students are sharing single server, then each
user created different dbf file in the c:temp- otherwise “already
.dbf” file exist error will occur.
For example: ‘c:tempuser1.dbf’. .c:tempuser2.dbf’

DROP TABLE SPACE

Dr.Girija Narasimhan 8
You can drop a tablespace and its contents (the segments contained
in the tablespace) from the database if the tablespace and its
contents are no longer required
Once a tablespace has been dropped, the data in the tablespace is
not recoverable.
Therefore, make sure that all data contained in a tablespace to be
dropped will not be required in the future
SQL> drop tablespace ica;
This will drop the tablespace only if it is empty

Tablespace is not empty and if you want to drop it anyhow then add
the following keyword
SQL>drop tablespace ica including contents;
This will drop the tablespace even if it is not empty.
But the data files will not be deleted you have to use operating
system command to delete the files.
But If you include data files keyword then, the associated data files
will also be deleted from the disk.
SQL>drop tablespace ica including contents and
datafiles;

various types of partition

CREATE TABLE <Table name>
RANGE PARTITION LIST
PARTITION
HASH
PARTITION
RANGE PARTITION
Using Number Values
RANGE PARTITION
Using Alphabet Values
RANGE PARTITION
Using DATE Values
Partition Type Partition
Type
Partition Type
COMPOSITE
PARTITION

RANGE PARTITION
Using Number Values

create table interval_part(pid number(5) not null,
fname varchar2(30),
lname varchar2(30) )
partition by range(pid)
(
partition p1 values less than(101)
)
tablespace dwuser01a;
Insert into INTERVAL_PART values(100,’Ali’,’Ahmed’);
Insert into INTERVAL_PART values(101,’Zahra’,’Khamis’);
PARTITION TYPE
PARTITION NAME
COLUMN NAME
Insert values into the interval_part and check whether the records are storing in the assign
partition
As per given condition, the maximum value is 100, it will store only the first record only. It
will give error message, for the value of product id 101 no partition was assigned

SELECT PARTITION_NAME, TABLESPACE_NAME, HIGH_VALUE FROM USER_TAB_PARTITIONS;
PARTITION_NAME TABLESPACE_NAME HIGH_VALUE
-----------------------------------------------------------------------------
P1 dwuser01a 101
SELECT * FROM INTERVAL_PART PARTITION(P1);
PID FNAME LNAME
---------- --------------- -----------------
100 Ali Ahmed
Insert into interval_part values(101,'zahra','khamis')
*
ERROR at line 1:
ORA-14400: inserted partition key does not map to any
partition
The USER_TAB_PARTITIONS describes the partition information as name of the
partition, tablespace name, storage parameter or value range of the partition .
Display the values stored in the partition.

RANGE PARTITION
Using Alphabet Values

Create table product_alpha(Pid number(4) primary key , pname
varchar2(25),pcategory varchar2(20))
PARTITION BY RANGE(pcategory)(
Partition pcategoy_ae VALUES LESS THAN(‘F%’) TABLESPACE part1,
Partition pcategoy_fl VALUES LESS THAN(‘M%’) TABLESPACE part2,
Partition pcategoy_mr VALUES LESS THAN(‘S%’) TABLESPACE part3,
Partition pcategoy_sz VALUES LESS THAN(MAXVALUE) TABLESPACE part4);
Range partition using partition key based on character based values.
This type of partition is useful for based on location name, country
and supplier based analysis in the data warehousing.
This is the alternative to numeric based values.
It will store the values “a,b,c,d,e”
It will store the exceed
values of all the partition
Store each partition in
different tablespace

SELECT PARTITION_NAME,TABLESPACE_NAME,HIGH_VALUE FROM
USER_TAB_PARTITIONS;
----------------------------- -------------------------------- -------------------
PCATEGOY_SZ PART4 MAXVALUE
PCATEGOY_AE PART1 'F%'
PCATEGOY_FL PART2 'M%'
PCATEGOY_MR PART3 'S%‘
Insert into Product_alpha values(100,’Sony LCD 32”’,’TV’);
Insert into Product_alpha values(200,’Sony POWER SHOT’,’CAMERA’);
Insert into Product_alpha values(300,’Sony 3G Dual SIM’,’MOBILE’);
Insert into product_alpha values(400,’Cannon Digit power’,’DIGITAL CAMERA’);

SELECT * FROM Product_alpha PARTITION(PCATEGOY_AE);
PID PNAME PCATEGORY
---------- --------------------------- --------------------
200 Sony POWER SHOT CAMERA
400 Cannon Digit power DIGITAL CAMERA
SELECT * FROM Product_alpha PARTITION(PCATEGOY_FL);
no rows selected
SELECT * FROM Product_alpha PARTITION(PCATEGOY_MR);
PID PNAME PCATEGORY
---------- ------------------------- --------------------
300 Sony 3G Dual SIM MOBILE
SELECT * FROM Product_alpha PARTITION(PCATEGOY_SZ);
PID PNAME PCATEGORY
--------- ------------------------- --------------------
100 Sony LCD 32” TV

RANGE PARTITION
Using DATE Values

CREATE TABLE Productrange_date (
Pid number(4) Primary key,pname varchar2(25),expdate date NOT Null)
PARTITION BY RANGE(expdate)(
PARTITION yr0 VALUES LESS THAN (TO_DATE('01-JAN-2007','DD-MON-YYYY')) TABLESPACE part1,
PARTITION yr3 VALUES LESS THAN (MAXVALUE) TABLESPACE part4);
INSERT INTO Productrange_date VALUES (1001, ‘Orange’, ’21-MAY-08’);
INSERT INTO Productrange_date VALUES (1002, ‘Sugar’, ’16-MAY-09’);
INSERT INTO Productrange_date VALUES (1003, ‘Biscutt’, ’12-NOV-09’);
SQL> select * from productrange_date;
PID PNAME EXPDATE
---------- ------------------------- -------------
1001 Orange 21-MAY-08
1002 Sugar 16-MAY-09
1003 Biscutt 12-NOV-09
The partition key in the range partition to be Date based.
It is useful for analyzing table data week wise or day wise.
Store values upto 31-dec-2006

SELECT * FROM productrange_date PARTITION(yr1);
no rows selected
PID PNAME EXPDATE
---------- -- ------------- -------------
PID PNAME EXPDATE
--------- --------------- -------------

ALTER TABLE
ADD PARTITION

ALTER TABLE <Table name>
ADD PARTITION
RANAME PARTITION
DROP PARTITION
MERGE PARTITION

ADD PARTITION
Using Alter table – ADD Partition statement, it is possible to
insert new partition details of already existed partition
Alter table INTERVAL_PART
ADD partition p2 values less than(201);
SELECT PARTITION_NAME,TABLESPACE_NAME,HIGH_VALUE FROM
USER_TAB_PARTITIONS;
-------------------------- ---------------- -----------------
P1 UWDATA 101
P2 UWDATA 201

SELECT * FROM INTERVAL_PART partition(P1);
PID FNAME LNAME
---------- ------------------------- --------------
100 Ali Ahmed
SELECT * FROM INTERVAL_PART partition(P2);
PID FNAME LNAME
---------- ------------------------- --------------
101 Zahra Khamis
200 Mohammed Omar
Insert into INTERVAL_PART values(101,'zahra','khamis');
Insert into INTERVAL_PART values(200,'Mohammed','omar');
SELECT * FROM INTERVAL_PART;
PID FNAME LNAME
---------- ------------------------- --------------
100 Ali Ahmed
101 Zahra Khamis
200 Mohammed Omar

ALTER TABLE
RENAME PARTITION

ALTER TABLE INTERVAL_PART
RENAME PARTITION P1 TO P9;
SQL> SELECT partition_name FROM user_tab_partitions WHERE
PARTITION_NAME='P9';
PARTITION_NAME
--------------------------
P9
SQL> SELECT * FROM INTERVAL_PART partition(P9);
PID FNAME LNAME
---------- -------------- ---------------
100 Ali Ahmed

ALTER TABLE
MERGE PARTITION

PID PNAME EXPDATE
---------- -- ------------- -------------
PID PNAME EXPDATE
--------- --------------- -------------
Alter table productrange_date merge partitions yr2,yr3
into partition yr6;
SELECT * FROM productrange_date PARTITION(yr6)
PID PNAME EXPDATE
--------- ------------------ ---------
Merge partition
creates a new
partition called yr6
It copies the values
from yr2 and yr3

ALTER TABLE
DROP PARTITION

Alter table Product_alpha drop partition pcategoy_ae;
SELECT * FROM Product_alpha PARTITION(PCATEGOY_AE);
PID PNAME PCATEGORY
---------- --------------------------- --------------------
SELECT * FROM Product_alpha;
PID PNAME PCATEGORY
---------- ----------------------------- --------------------
100 Sony LCD 32" TV

SELECT * FROM Product_alpha;
PID PNAME PCATEGORY
---------- ----------------------------- --------------------
100 Sony LCD 32" TV
it merely updates the data dictionary to indicate that the
pcategoy_AE partition no longer belongs to the
Product_alpha table.
It also remove the partition values from the table.

LIST PARTITION

The syntax of list partition is three parts:
1) partition method: Partition by list
2) Specify the partition column, example (slocation)
3) Partition description: Partition “partition_name” values (list of values)
list partition is organizing the data allows unordered and unrelated
sets of data to be grouped and organized together.
It is controls each and every row values and mapping with partition
CREATE TABLE STORE_LIST(
STORENO NUMBER(5)PRIMARY KEY,STORENAME VARCHAR2(20),
SPROFIT NUMBER(5),SLOCATION VARCHAR2(15),SDATE DATE)
PARTITION BY LIST (SLOCATION)
(
PARTITION LOC_Muscat VALUES(‘Al-khuwair’,’Ruwi’),
PARTITION LOC_Al Batinah VALUES(‘Barka’, ‘Musannah’),
PARTITION LOC_Dakhliyah VALUES(‘Nizwa’,’ Sumail’));

SELECT * FROM STORE_LIST;
STORENO STORENAME SPROFIT SLOCATION SDATE
-----------------------------------------------------------
11 RELIANCE FRESH 5000 Al-khuwair 10-APR-09
13 SPENCER PLAZA 6000 Nizwa 18-DEC-05
12 RELIANCE FRESH 4500 Barka 12-SEP-07
15 Apollo Medical 3000 Musanna 21-JUN-06
14 Apollo Medical 8000 Ruwi 24-DEC-08
SELECT * FROM STORE_LIST PARTITION(LOC_Muscat);
-----------------------------------------------------------
SELECT * FROM STORE_LIST PARTITION(LOC_Al_Batinah);
-----------------------------------------------------------
SELECT * FROM STORE_LIST PARTITION(LOC_Dakhliyah);
-----------------------------------------------------------

LIST PARTITION
ADD PARTITION USING “DEFAULT” VALUE

The special capability of list partition is default partition.
The benefit of using default partition is, it don’t generate an
error suppose all rows don’t map with any partition in the list.
Using alter table statement, it is possible to add new partition
in the already existed list partition.
ALTER TABLE STORE_LIST
ADD PARTITION LOC_OTHER
VALUES(DEFAULT)TABLESPACE PART4;
INSERT INTO STORE_LIST VALUES(16,'SPENCER PLAZA',4300,
‘Salalah',’29-MAY-2004’);
SELECT * FROM STORE_LIST PARTITION(LOC_OTHER);
-------- -------------- -------- ---------- --------
16 SPENCER PLAZA 4300 Salalah 29-MAY-04

ALTER TABLE
MODIFY PARTITION
ADD “List values”

ALTER TABLE <table Name> MODIFY PARTITION
ADD “List values”
It will add new values in the already existing
partition.
Like update statement, it will change the
specific values of the table
DROP “List values”
Remove the specific value from the already
existing partition.
Like delete statement, how it will delete
specific information from the table.
Values of the partition

ALTER TABLE STORE_LIST MODIFY PARTITION LOC_Muscat
ADD VALUES (' Bowsher ', ' Seeb ');
INSERT INTO STORE_LIST VALUES(17,'SPENCER PLAZA',3300, 'seeb',’02-APR-2004’);
SELECT * FROM STORE_LIST PARTITION(LOC_Muscat);
---------- -------------------- ------------- ------------------ -------------
17 SPENCER PLAZA 3300 seeb 02-APR-04
In the list partition “LOC_MUSCAT” partition had values “SEEB,
BOWSHER”.
Suppose to change already existed list value in the list partition,
use ALTER TABLE –MODIFY statement to change the new values.

ALTER TABLE
MODIFY PARTITION
DROP “List values”

Suppose to remove particular list value from the partition, that
partition has the specific values then oracle trigger the error.
The partition doesn’t have that values or data then error free.
Avoiding the error message, first delete the specific values in the
partition and then drop the values from the list partition.
MODIFY PARTITION LOC_Muscat
DROP VALUES(‘Ruwi’);
ERROR at line 1:
ORA-14518: partition contains rows corresponding to values being
dropped
Delete from store_list where storeno=14
MODIFY PARTITION LOC_Muscat
DROP VALUES (‘Ruwi’);

TRUNCATE PARTITION

Truncate statement delete all the values in the mentioned partition.
So, partition which is truncated is empty or without any value. So
error don’t occur like drop values.
But it will retain the Partition without values.
Alter table STORE_LIST truncate partition LOC_Muscat DROP STORAGE;
select * from store_list;
---------- -------------------- ---------- --------------------------

MOVE PARTITION

ALTER TABLE products MOVE PARTITION PARTNO1 TABLESPACE
uwdata;
select tablespace_name,partition_name from
user_tab_partitions where table_name='PRODUCTS';
TABLESPACE_NAME PARTITION_NAME
------------------------------ ------------------------
UWDATA PARTNO1
PART2 PARTNO2
PART3 PARTNO3
select tablespace_name,partition_name from
user_tab_partitions where table_name='PRODUCTS';
TABLESPACE_NAME PARTITION_NAME
------------------------------ ------------------------
PART1 PARTNO1
PART2 PARTNO2
PART3 PARTNO3
Here tablespace name is case sensitive. Now “PARTNO1” partition is moved
from tablespace “PART1” to “UMDATA”.
It will move the most active partition to a tablespace. It also create new segment for
the tablespace for the moving partition and it also drops the moved partition's
Previous segment.

SPLIT PARTITION

It splits the partition into more than one and also move the
specified values into corresponding split partition
--------------------------------- -------------------------
18 Apollo Medical 8000 Ibra 24-DEC-08
19 Apollo Medical 3000 Ibra 21-JUN-06
20 SPENCER PLAZA 4300 Shinas 29-MAY-04
21 SPENCER PLAZA 4300 Amrath 29-MAY-04
SPLIT PARTITION LOC_OTHER VALUES('Ibra')
INTO (PARTITION LOC_Ibra,PARTITION LOC_OTHER);

SELECT * FROM STORE_LIST PARTITION(LOC_Ibra);
---------- ------------------------------------------------
18 Apollo Medical 8000 Ibra 24-DEC-08
19 Apollo Medical 3000 Ibra 21-JUN-06
---------- ------------------------------------------------
20 SPENCER PLAZA 4300 Shinas 29-MAY-04
21 SPENCER PLAZA 4300 Amrath 29-MAY-04

HASH PARTITION

Hash partition is using hashing algorithm.
The key feature of hashing algorithm into it evenly distributes rows
among partitions, so all the partitions are almost the same size.
This feature is useful for spreading the data into sufficient number of
devices to maximizing the I/O devices.
The oracle database uses a linear hashing algorithm.
Suppose any add or merge a hashed partition, the oracle
automatically rearranges the rows within the partition and sub
partition.

CREATE TABLE products(partno NUMBER,
description VARCHAR2 (60))
PARTITION BY HASH (partno)
(PARTITION partno1 TABLESPACE part1,
PARTITION partno2 TABLESPACE part2,
PARTITION partno3 TABLESPACE part3,
PARTITION partno4 TABLESPACE part4);
Insert into products values(11,’ice cream’);
Insert into products values(12,’coffee’);
Insert into products values(13,’tea’);
Insert into products values(14,’sugar’);

SELECT * FROM products partition(partno1);
PARTNO DESCRIPTION
---------- ------------------------------------
11 ice cream
13 tea
PARTNO DESCRIPTION
---------- -----------------------------------
12 coffee
PARTNO DESCRIPTION
---------- -----------------------------------
14 sugar

HASH PARTITION
Using Coalescing

Select table_name, partition_name from
user_tab_partitions where TABLE_NAME='PRODUCTS';
TABLE_NAME PARTITION_NAME
------------------------------ ------------------------
PRODUCTS PARTNO1
PRODUCTS PARTNO2
PRODUCTS PARTNO3
PRODUCTS PARTNO4
PARTNO DESCRIPTION
---------- -------------------------------------------
14 sugar
PARTNO DESCRIPTION
---------- --------------------------------------
12 coffee

Coalescing partitions is a way of reducing
the number partitions in a hash-partitioned
table.
When a hash partition is coalesced, its
contents are redistributed into one or more
remaining partitions determined by the hash
function.
The specific partition that is coalesced is
selected by oracle, and is dropped after
its contents have been redistributed.

ALTER TABLE PRODUCTS COALESCE PARTITION;
SQL> Select table_name, partition_name from
user_tab_partitions where TABLE_NAME='PRODUCTS';
TABLE_NAME PARTITION_NAME
------------------------------ ----------------------
PRODUCTS PARTNO1
PRODUCTS PARTNO2
PRODUCTS PARTNO3
SQL> SELECT * FROM products partition(partno2);
PARTNO DESCRIPTION
---------- ------------------------------------------
12 coffee
14 sugar
Here PARTNO4 is dropped and PARTNO4 partition values are distributed into
PARTNO2 partition.

Compare
Truncate, Drop list values, Drop,Coalsec

Truncate
Partition
Drop Partition
coalesce
Drop List value
It retains the
partition, but
deletes all
values from the
partition or from
the table. So,
partition
without any
value or empty.
It will drop partition and
the values also.
It will delete the
partition and
redistribute the
value to other
partition.
Suppose coalesce
partition p1, then
it will
redistributed the
p1 values or
information to
another partition
p2.
In the List partition, For
example
Loc_Muscat (‘Ruwi’,’Seeb’). I
want to delete only Ruwi
value. Suppose any one
record or row in the partition
have ruwi value.
Step1: delete the record
having ‘ruwi’ value from the
table. otherwise it will give
error.
Step 2: alter table modify
partition drop values (ruwi) .

COMPOSITE PARTITION

The types of composite partitioning are:
 Composite Range-Range Partitioning
 Composite Range-Hash Partitioning
 Composite Range-List Partitioning
 Composite List-Range Partitioning
 Composite List-Hash Partitioning
 Composite List-List Partitioning
 Composite Hash-Hash Partitioning
 Composite Hash-List Partitioning
 Composite Hash-Range Partitioning
Composite partitioning is a combination of the two partition method. Table is partitioned by
one data distribution method for example Range Partition. Each partition is further
subdivided into another Partition method for example List.

Conn hr/hr
CREATE TABLE STORE_COMPOSITLIST(
STORENO NUMBER(5)PRIMARY KEY,STORENAME VARCHAR2(20),
SPROFIT NUMBER(5),SLOCATION VARCHAR2(15),SDATE DATE)
PARTITION BY RANGE(STORENO)
SUBPARTITION BY LIST (SLOCATION)
SUBPARTITION TEMPLATE(
SUBPARTITION LOC_Muscat VALUES (‘Al-khuwair’,’Ruwi’) TABLESPACE part1
SUBPARTITION LOC_Dakhliyah VALUES (‘Nizwa’,’Sumail’)TABLESPACE part1)
(
partition p1 values less than(13),
partition p2 values less than(maxvalue));
Composite Partitioned Table - By
Range And List
CREATE TABLESPACE part1
DATAFILE 'c:temppart1.dbf' SIZE 40M
BLOCKSIZE 8192
EXTENT MANAGEMENT LOCAL UNIFORM SIZE 256K
SEGMENT SPACE MANAGEMENT AUTO ONLINE;
Conn sys as sysdba
sys

• Partition Type : RANGE
• Partition Key column: STORENO
• Sub partition Type: LIST
• Sub partition key column : SLOCATION
• Sub partition: LOC_Muscat , LOC_Dakhliyah
• Sub partition Values :
LOC_Muscat VALUES (‘Al-khuwair’,’Ruwi’)
LOC_Dakhliyah VALUES (‘Nizwa’,’Sumail’)
• Partition Name and Values: p1 (value <13), p2 (Maxvalue)
Components of composite partition

set linesize 450;
SELECT table_name, partition_name, composite, high_value
FROM user_tab_partitions;
insert into store_compositlist values(11,'Reliance Fresh',500,'Al-khuwair','10-apr-17');
insert into store_compositlist values(12,'Reliance Fresh',450,'Sumail','12-sep-17');
insert into store_compositlist values(13,'Spencer Plaza',600,'Nizwa','11-Nov-17');
insert into store_compositlist values(14, 'Apollo Medical',300,'Ruwi','21-Jun-17');
insert into store_compositlist values(15,'Apollo Medical',800,'Ruwi','27-may-17');
Display the partition Information

SELECT table_name, partition_name, subpartition_name,
num_rows FROM user_tab_subpartitions;
Display the sub partition information
Here Num_rows column is empty. For getting values in the Num_rows column analyze the
statistics.

Display the Partition values in the partition P1 and P2

Display the Sub Partition values, don’t give sub partition name, then it will give error
message. <partition name> _<subpartition name> in the select statement

PARTITIONED INDEX

Local Partitioned Index
Global Partitioned Index
Partitioned Indexes

Dr.Girija Narasimhan
71
Partitioned Indexes
Local Index Global Index
one-to-one mapping between a index
partition and a table partition
(equipartitioned)
created with the LOCAL keyword and support
partition independence
one-to-many relationship, allowing one index
partition to map to many table partitions
number of index partitions will match the
number of partitions in the base table.
index partition gets deleted when the
underlying table partition dropped, can’t
drop partition index
Drop a non-empty global index partition will
cause the next highest partition to be marked
unusable.
Column mentioned in the partition index is
not primary key column but it must be “NOT
NULL” column.
Local Non-Prefixed
Indexes
Local Prefixed Indexes
indexed column does not
match the partition key
indexed column match
the partition key
At least one partition should have MAX
VALUE
Global Index don’t have Non-
prefixed Indexes

CREATE INDEX <index_name>
ON <table_name> <column_name_list>
LOCAL
Partition(partition name);
The primary key column not allowed for indexing
Same partition name as given in the
table.
Local Index

Local
Prefixed
Indexes

Local Non-
Prefixed
Indexes
Display the Status of the partition index

Dropping the Partition from the Local index is not allowed.
Instead of dropping from index, drop the partition from the table, it automatically drop
the partition from the index.

Global Index
In the global
index max
value should
be include in
partition.

Display the status of the global index
Unlike local index, it is possible to remove or drop partition from the global index

Entire global index can’t be rebuild, only specific partition to be rebuild is possible.
Partition name actual name given in
the index no need to mention
indexname_partition name.

https://www.morganslibrary.org/reference/partitions.html#rlp
http://www.acehints.com/2011/06/global-index-vs-local-index-difference.html
https://oracle-base.com/articles/8i/partitioned-tables-and-indexes
References

OER UNIT 4 PARTITION

More Related Content

What's hot (20)

Similar to OER UNIT 4 PARTITION (20)

More from Girija Muscut (20)

Recently uploaded (20)

OER UNIT 4 PARTITION